Chelsea Physic Garden: edible and educational

London has a new garden, and it's a stunner. The half-acre Garden of Edible and Useful Plants is as fascinating as it is beautiful: its spectacular Andalucian orange trees alone are worth your visit.

Its location is in the much-loved Chelsea Physic Garden, and it is the first significant addition to the capital's oldest botanic garden for more than a century. The aim of the garden is to bring us closer to the plants on which humanity depends.

The kitchen garden at Chelsea Physic Garden gives visitors surprising insights into the uses of plants

Thus you can wander around the raised beds that hold each group of plants and discover, through the information panels, that the seed heads of burdock led to the hook-and-eye technology of Velcro (Science and Research bed), the Romans used verbascum flower spikes, dipped in tallow, for slow-burn torches (Housing bed) and the fierce spines of prickly pear cactus were used to play records on early gramophones before steel needles (Arts and Culture bed).

A bamboo thicket, contained within a metre-deep rhizome barrier, represents the world's most useful plant, and the accompanying panel offers up just some of its diverse uses: blinds, beer, hats, utensils, furniture, flooring, paper, medicine, charcoal.

Here, too, are cotton plants, their fluffy seed pods used to make celluloid film; here are a clutch of calla lilies, their seeds used in maracas as well as bullets in the 19th-century Indian mutiny; here are potatoes alongside rice plants, featured as part of an alcohol plants collection — vodka or sake, anyone?

"Plants are our best resource. They're renewable, they're sustainable, they produce oxygen and they give us virtually everything we need to live, if we care to look at them hard enough," says head gardener Nick Bailey, 37, who has given us a terrific opportunity to do so, by designing the brick-paved garden — a series of interlinked spaces inspired by 18th-century potagers — and researching the plants and their properties over the past two years.

"We have great academic researchers at the Physic Garden as well as great gardeners," says Bailey, "but one of the biggest challenges was to find the plants that matched all those incredible properties: we could hardly stock up at B&Q.

Our links with other botanic gardens around the world helped, and we also contacted specialist nurseries that just might have the obscure plant we needed tucked in a corner. It was a huge task."

Foodies can read the story of the British wine industry, checking out the different vines in the compact vineyard to see which they might grow; boggle at the lion's mane mushrooms thriving on spore-impregnated logs; find different plant oils for cooking, such as camellia and rocket, as well as take notes in the Edible Garden on unusual vegetables to grow, such as the wild Galapagos tomato, beloved by the Galapagos tortoise — and maybe, next summer, by you.

The fragrant bench on which to absorb all these sights, and have yourself a grade-A aromatherapy hit, is within the stone amphitheatre of perfumery plants.

A field of lavender wraps around the curved dry-stone wall and the tiers of the amphitheatre hold potted delights such as almond-scented holy grass, the antique Damascus rose, vanilla-scented heliotrope, trailing rosemaries and the stroke-and-sniff Geranium graveolens, which smells distinctly of Turkish Delight. Tomatoes are also included because of the leaves that are used to spike aftershave.

Cardamom, the aromatic spice plant, survived last winter in the garden even though it's a southern Indian native, says Bailey, but with its celebrated micro-climate, south-facing aspect and free-draining soil, the Chelsea Physic Garden can grow almost anything and does, including a mature grapefruit tree, a thriving pomegranate tree and the largest fruiting olive tree in the UK.

A pretty flower-filled central bed, called Bee Forage, looks strictly ornamental, yet holds the key garden plants that will provide food for bees from early spring right through to the frosts: make a note to include gaillardia, long-flowering Geranium Rozanne and Erysimum Bowles's Mauve as well as sedums and diascias in future planting schemes.

The Land Restoration bed is arguably the most fascinating of all. It shows plants' capacities to extract toxic chemicals such as cadmium and selenium from the ground, so there is atriplex or salt bush, which removes saline from land flooded by sea, and, remarkably, sunflowers, because they were planted in Chernobyl after the disaster to remove radioactive particles from the soil.

Although many of the plants in the garden are featured because of their past credits, such as the ancient vegetable ramie, the fibres of which were used to make mummy cloths in Egypt, others are more up to date, such as soybean, used to make inexpensive ink that is easier to recycle and offers brighter colours.

A central pine, Pinus sylvestris, in the Science and Research bed, represents the current research on pine cones' characteristic of expanding and contracting in weather extremes, with the aim of using that property to make impermeable yet breathable fabrics for the future.

"There isn't another garden in the world doing quite what we're doing and we're very proud of this unique project," says Nick Bailey. He has every right to be.

Chelsea Physic Garden is at 66 Royal Hospital Road, SW3; the visitor entrance is in Swan Walk. Open Tuesday to Friday, noon to 5pm, and Sundays and Bank Holidays, noon to 6pm, from April 1 until October 31. For more information, visit chelseaphysicgarden.co.uk